Catheter with multi-functional control handle having linear mechanism

ABSTRACT

A catheter for use in a patient&#39;s heart, especially for mapping a tubular region of the heart, has a catheter body, a deflectable intermediate section and a distal a mapping assembly that has a generally circular portion adapted to sit on or in a tubular region of the heart. A control handle of the catheter allows for single-handed manipulation of various control mechanisms that can deflect the intermediate section and contract the mapping assembly by means of a deflection control assembly and a linear control assembly. The deflection control assembly has a deflection arm and a rocker member. The linear control assembly has a linear control member, an inner rotational member and a cam. A pair of puller members are responsive to the deflection control assembly to bi-directionally deflect the intermediate section. A third puller member is responsive to the linear control assembly to contract the generally circular portion of the mapping assembly.

FIELD OF INVENTION

This invention relates to a catheter, in particular, a catheter with acontrol handle having multiple control mechanisms for deflecting andcontracting portions of the catheter.

BACKGROUND

Electrode catheters have been in common use in medical practice for manyyears. They are used to stimulate and map electrical activity in theheart and to ablate sites of aberrant electrical activity. Atrialfibrillation is a common sustained cardiac arrhythmia and a major causeof stroke. This condition is perpetuated by reentrant waveletspropagating in an abnormal atrial-tissue substrate. Various approacheshave been developed to interrupt wavelets, including surgical orcatheter-mediated atriotomy. Prior to treating the condition, one has tofirst determine the location of the wavelets. Various techniques havebeen proposed for making such a determination, including the use ofcatheters with a mapping assembly that is adapted to measure activitywithin a pulmonary vein, coronary sinus or other tubular structure aboutthe inner circumference of the structure. One such mapping assembly hasa tubular structure comprising a generally circular main regiongenerally transverse and distal to the catheter body and having an outercircumference and a generally straight distal region distal to the mainregion. The tubular structure comprises a non-conductive cover over atleast the main region of the mapping assembly. A support member havingshape-memory is disposed within at least the main region of the mappingassembly. A plurality of electrode pairs, each comprising two ringelectrodes, are carried by the generally circular main region of themapping assembly.

In use, the electrode catheter is inserted into a guiding sheath whichhas been positioned a major vein or artery, e.g., femoral artery, andguided into a chamber of the heart. Within the chamber, the catheter isextended past a distal end of the guiding sheath to expose the mappingassembly. The catheter is maneuvered through movements that includedeflection of a distal portion of the catheter so that the mappingassembly is positioned at the tubular region in the heart chamber. Theability to control the exact position and orientation of the catheterand also the configuration of the mapping assembly is critical andlargely determines how useful the catheter is.

Steerable catheters are generally well-known. For example, U.S. Pat. No.Re 34,502 describes a catheter having a control handle comprising ahousing having a piston chamber at its distal end. A piston is mountedin the piston chamber and is afforded lengthwise movement. The proximalend of the elongated catheter body is attached to the piston. A pullerwire is attached to the housing and extends through the piston, throughthe catheter body, and into a tip section at the distal end of thecatheter body. The distal end of the puller wire is anchored in the tipsection of the catheter. In this arrangement, lengthwise movement of thepiston relative to the housing results in deflection of the catheter tipsection.

The design described in U.S. Pat. No. RE 34,502 is generally limited toa catheter having a single puller wire. If bi-directional deflection isdesire, more than one puller wire becomes necessary. Moreover, if morecontrol is desired, such as contraction of the mapping assembly, anadditional puller wire is needed. Space is limited within a controlhandle and operation of puller wire control mechanisms must notinterfere with components that extend through the control handle, suchas lead wires, cables, and irrigation tubing. Moreover, it is desirablethat the control mechanisms be arranged such that the catheter can beoperated single-handedly by the user. Accordingly, a need exists for acontrol handle capable of moving three puller wires for at least twoindependent movements, such as bi-directional deflection of the cathetershaft and contraction of the mapping assembly, preferably through asingle-handed manipulation of the user.

SUMMARY OF THE INVENTION

The present invention is directed to a catheter for use in a patient'sheart, especially for mapping a tubular region of the heart. In oneembodiment, the catheter has a catheter body and a deflectableintermediate section distal the catheter body. Distal the intermediatesection is a mapping assembly that has a generally circular portionadapted to sit on or in a tubular region of the heart. A control handleof the catheter allows for single-handed manipulation of various controlmechanisms that can deflect the intermediate section and contract themapping assembly by means of a deflection control assembly and a linearcontrol assembly. The deflection control assembly has a deflection armand a rocker member. The linear control assembly has a linear controlmember, an inner rotational member and a cam. A pair of puller membersare responsive to the deflection control assembly to bi-directionallydeflect the intermediate section. A third puller member is responsive tothe linear control assembly to contract the generally circular portionof the mapping assembly.

In a more detailed embodiment, a proximal end of the third puller memberis anchored in the linear control assembly, such that actuation of thelinear control member by a user moves the third puller memberlongitudinally relative to the catheter body. The linear control memberhas a portion that slidably engages housing of the control handle, and aprojection that is received in a track formed on the inner rotationalmember such that distal and proximal movement of the control memberalong the longitudinal axis of the control handle rotates the innerrotational member to expand or retract the mapping assembly. Situatedbetween the inner rotational member and the cam, a follower to which aproximal end of the third puller member is anchored is guided by a slotformed in the inner rotational member so as to slide in a cam trackformed on the cam. Both the cam track and the track formed on the innerrotational member are helical to maximize efficiency of the linearcontrol assembly in occupying a relatively small space in the controlhandle to achieve the linear motion desirable for expanding andcontracting mapping assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and advantages of the present invention will bebetter understood by reference to the following detailed descriptionwhen considered in conjunction with the accompanying drawings. It isunderstood that selected structures and features have not been shown incertain drawings so as to provide better viewing of the remainingstructures and features.

FIG. 1 is a top plan view of one embodiment of the catheter of thepresent invention.

FIG. 2 a is a side cross-sectional view of an embodiment of a junctionof a catheter body and an intermediate section, taken along a firstdiameter.

FIG. 2 b is a side cross-sectional view of the embodiment of thejunction of FIG. 2 a, taken along a second diameter generallyperpendicular to the first diameter.

FIG. 3 is a side view of a distal portion of the catheter of FIG. 1,including an intermediate section and a mapping assembly.

FIG. 4 is a longitudinal cross-sectional view of the intermediatesection of FIG. 3, taken along line 4-4.

FIG. 5 is a schematic view of the mapping assembly showing onearrangement of the ring electrodes.

FIG. 6 is a longitudinal cross-sectional view of the mapping assembly ofFIG. 3 along line 6-6.

FIG. 7 is a side cross-sectional view of an embodiment of a distal endof the mapping assembly of FIG. 3.

FIG. 8 a is a side cross-sectional view of an embodiment of a junctionbetween the intermediate section and the mapping assembly, taken along afirst diameter.

FIG. 8 b is a side cross-sectional view of an embodiment of a junctionbetween the intermediate section and the mapping assembly, taken along asecond diameter generally perpendicular to the first diameter.

FIG. 9 is a top plan view of an embodiment of a control handle housinghalf including an embodiment of a deflection control assembly.

FIG. 10 is a top perspective view of an embodiment of a rocker member ofa deflection control assembly.

FIG. 11 is a bottom perspective view of an embodiment of a rockermember.

FIG. 12 is a side view of an embodiment of a pulley of a deflectioncontrol assembly.

FIG. 13 a-13 c are schematics of an embodiment of the deflection controlassembly in neutral and rotated configurations.

FIG. 14 is a longitudinal cross section of an embodiment of thedeflection control assembly and tension control assembly mounted on acontrol handle.

FIG. 14 a is a detailed view of a portion of FIG. 14, including anembodiment of a retaining nut and a tension screw.

FIG. 15 is a partial perspective view of an embodiment of a firstcontrol handle housing half.

FIG. 16 is a perspective view of an embodiment of a deflection arm.

FIG. 17 is a perspective view of an embodiment of a tension controldial.

FIG. 18 is a perspective view of an embodiment of a locking plate.

FIG. 19 is a partial perspective view of a portion of an embodiment of acontrol handle.

FIG. 20 is a partial perspective view of a portion of an embodiment of adeflection arm and a tension control member mounted on a control handle.

FIG. 21 is a partial perspective view of a portion of an embodiment of asecond control handle housing half and a retaining nut, the secondcontrol housing half adapted to oppose the first control handle housinghalf.

FIG. 22 is a perspective view of the tension control dial of FIG. 17 andlocking plate of FIG. 18 as assembled.

FIG. 23 is an exploded perspective view of an embodiment of a linearcontrol assembly.

FIG. 24 is a side cross-sectional view of the linear control assembly ofFIG. 23, as assembled on a control handle.

FIG. 25 is a longitudinal cross-sectional view of the linear controlassembly of FIG. 24, taken along line a-a.

FIG. 26 is a longitudinal cross-sectional view of the linear controlassembly of FIG. 24, taken along line b-b.

FIG. 27 is a longitudinal cross-sectional view of the linear controlassembly of FIG. 24, taken along line c-c.

FIG. 28 is a side cross-sectional view of an alternate embodiment of thelinear control assembly, as assembled on a control handle.

FIG. 29 is a longitudinal cross-sectional view of the linear controlassembly of FIG. 28, taken along line a-a.

FIG. 30 is a longitudinal cross-sectional view of the linear controlassembly of FIG. 28 taken along line b-b.

FIG. 31 is a longitudinal cross-sectional view of the linear controlassembly of FIG. 28, taken along line c-c.

FIG. 32 is a partial perspective view of an alternate embodiment of acontrol handle housing half.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, the present invention is directed to a catheter 10with multiple control capabilities for mapping and/or ablation of theheart. In the illustrated embodiment of FIG. 1, a catheter 10 comprisesan elongated catheter body 12, a deflectable intermediate section 14 ata distal end of the catheter body 12, a tip section 15 including amapping assembly 17 at a distal end of the intermediate section 14, anda multi-functional control handle 16 at a proximal end of the catheterbody 12 for controlling portions of the catheter, for example,deflecting the intermediate section 14 and contracting the mappingassembly 17.

With reference to FIGS. 2A and 2B, the catheter body 12 comprises asingle, central or axial lumen 18. The catheter body 12 is flexible,i.e., bendable, but substantially non-compressible along its length. Thecatheter body 12 may be of any suitable construction and made of anysuitable material. In one embodiment, the catheter body 12 comprises anouter wall 22 made of a polyurethane or nylon. The outer wall 22comprises an imbedded braided mesh of stainless steel or the like toincrease torsional stiffness of the catheter body 12 so that, when thecontrol handle 16 is rotated, the tip section of the catheter 10 willrotate in a corresponding manner.

The outer diameter of the catheter body 12 is not critical, but ispreferably no more than about 8 French. Likewise the thickness of theouter wall 22 is not critical. The inner surface of the outer wall 22 islined with a stiffening tube 20, which can be made of any suitablematerial, preferably polyimide. The stiffening tube 20 is held in placerelative to the outer wall 22 at the proximal end of the catheter body12. A first glue joint 23 is made between the distal ends of thestiffening tube 20 and the outer wall 22 by a fast drying glue, e.g.Super Glue®. Thereafter a second glue joint 25 is formed between theproximal ends of the stiffening tube 20 and outer wall 22 using a slowerdrying but stronger glue, e.g., polyurethane.

The stiffening tube, along with the braided outer wall 22, providesimproved torsional stability while at the same time minimizing the wallthickness of the catheter, thus maximizing the diameter of the singlelumen. The outer diameter of the stiffening tube 20 is about the same asor slightly smaller than the inner diameter of the outer wall 22.Polyimide tubing is suitable because it may be very thin walled whilestill providing very good stiffness. This maximizes the diameter of thecentral lumen 18 without sacrificing strength and stiffness. Polyimidematerial is typically not used for stiffening tubes because of itstendency to kink when bent. However, it has been found that, incombination with an outer wall 22 of polyurethane, nylon or othersimilar material, particularly having a stainless steel braided mesh,the tendency for the polyimide stiffening tube 20 to kink when bent isessentially eliminated with respect to the applications for which thecatheter is used.

In one embodiment, the outer wall 22 has an outer diameter of about0.092 inch and an inner diameter of about 0.063 inch and the polyimidestiffening tube 20 has an outer diameter of about 0.0615 inch and aninner diameter of about 0.052 inch.

As shown in FIGS. 2A, 2B and 4, the intermediate section 14 comprises ashorter section of tubing 19 with multiple off-axis lumens, for example,first, second, third and fourth lumens 30, 31, 32 and 33. The tubing 19is made of a suitable non-toxic material which is preferably moreflexible than the catheter body 12. A suitable material for the tubing19 is braided polyurethane, i.e., polyurethane with an embedded mesh ofbraided stainless steel or the like. The outer diameter of theintermediate section 14, like that of the catheter body 12, ispreferably no greater than about 8 French. The size of the lumens is notcritical. In one embodiment, the intermediate section has an outerdiameter of about 7 French (0.092 inch) and the lumens are generallyabout the same size, having a diameter of about 0.022 inch, or selectedlumens can have a slightly larger diameter of about 0.036 inch.

A means for attaching the catheter body 12 to the intermediate section14 is illustrated in FIGS. 2A and 2B. The proximal end of theintermediate section 14 comprises an inner counter bore 24 that receivesthe outer surface of the polyimide stiffener 20. The intermediatesection 14 and catheter body 12 are attached by glue 29 or the like.

As shown in FIGS. 2A and 2B, extending through the single lumen 18 ofthe catheter body 12 are various components, for example, lead wires andmultiple puller members, and any other wires or cables. Longitudinalmovement of the puller members relative to the catheter body 12 enableuser control of various parts of the catheter via the control handle. Inone embodiment, the puller members include a pair of deflection pullermembers 42 for deflecting the intermediate section 14 and a contractionpuller member 35 for adjusting the mapping assembly 17 of the tipsection 15.

A single lumen catheter body 12 may be preferred over a multi-lumen bodybecause the single lumen 18 body can permit better tip control whenrotating the catheter 10. The single lumen 18 permits the componentspassing therethrough to float freely within the catheter body. If suchcomponents were restricted within multiple lumens, they can build upenergy when the handle 16 is rotated, resulting in the catheter body 12having a tendency to rotate back if, for example, the handle isreleased, or if bent around a curve, to flip over, either for which areundesirable performance characteristics.

A deflection puller member 42 extends through the central lumen 18 ofthe catheter body 12 and into the second lumen 31 of the intermediatesection 14. Another deflection puller member 42 extends through thecentral lumen 18 and into the fourth lumen 33 of the intermediatesection 14. The distal ends of the deflection puller members 42 areanchored to the wall of the tubing 19 near the distal end of theintermediate section 14 by means of T-anchors 83 (FIG. 8B). In theintermediate section 14, each deflection puller members 42 extendsthrough a plastic, e.g. Teflon®, sheath 81, which prevents thedeflection puller members 42 from cutting into the wall of the tubing 19of the intermediate section 14 when the intermediate section 14 isdeflected.

As shown in FIG. 2B, compression coils 44 in surrounding relation to thedeflection puller members 42 extend from the proximal end of thecatheter body 12 to the proximal end of the intermediate section 14. Thecompression coils 44 are made of any suitable metal, e.g., stainlesssteel. The compression coils 44 are tightly wound on itself to provideflexibility, i.e., bending, but to resist compression. The innerdiameter of the compression coils 44 is preferably slightly larger thanthe diameter of the puller wires 42. For example, when a puller member42 has a diameter of about 0.007 inches, the compression coil 44preferably has an inner diameter of about 0.008 inches. The Teflon®coating on the puller member 42 allows them to slide freely within thecompression coils 44. The outer surface of the compression coils 44 iscovered by a flexible, non-conductive sheath 27 to prevent contactbetween the compression coils 44 and other components, such as leadwires and cables, etc. In one embodiment, a non-conductive sheath ismade of polyimide tubing.

The compression coils 44 are anchored at their proximal ends to theproximal end of the stiffening tube 20 in the catheter body 12 by gluejoint 50 (FIG. 2B) and at its distal end near the proximal end of theintermediate section 14 in the second lumen 31 and fourth lumen 33 byglue joints 49 (FIG. 2B).

With reference to FIG. 3, at the distal end of the intermediate section14 is the mapping assembly 17. The mapping assembly 17 comprises agenerally straight proximal region 38 and a generally circular mainregion 39. The proximal region 38 is mounted on the intermediate section14, as described in more detail below, so that its axis can be a linearaxial extension of the intermediate section 14. The proximal region 38has an exposed length, e.g., not contained within the intermediatesection 14, ranging from about 3 mm to about 12 mm, more preferablyabout 3 mm to about 8 mm, still more preferably about 5 mm, but can varyas desired.

The generally circular main region 39 is generally traverse, if not alsoperpendicular, to the catheter body 12 and the intermediate section 14.The generally circular main region 39 can form a flat circle or can bevery slightly helical. The main region 39 has an outer diameterpreferably ranging from about 10 mm to about 25 mm, more preferablyabout 12 mm to about 20 mm. The generally circular main region 39 cancurve in a clockwise direction or a counterclockwise direction. As shownin FIGS. 5, 6 and 7, the mapping assembly 17 is formed of anon-conductive cover or tubing 52 which can have any cross-sectionalshape as desired. The non-conductive cover 52 can be made of anysuitable material, and is preferably made of a biocompatible plasticsuch as polyurethane or PEBAX. The non-conductive cover 52 can bepre-formed into the desired generally circular shape of the generallycircular main region 39. Alternatively, the shape of the generallycircular main region 39 can be defined by a wire or other componentextending through the non-conductive cover 52.

In the depicted embodiment, a pre-formed support member 54 extendsthrough the non-conductive cover 52 to define the shape of the generallycircular main region 39. The support member 54 is made of a materialhaving shape-memory, i.e., that can be straightened or bent out of itsoriginal shape upon exertion of a force and is capable of substantiallyreturning to its original shape upon removal of the force. A suitablematerial for the support member 54 is a nickel/titanium alloy. Suchalloys typically comprise about 55% nickel and 45% titanium, but maycomprise from about 54% to about 57% nickel with the balance beingtitanium. A suitable nickel/titanium alloy is Nitinol, which hasexcellent shape memory, together with ductility, strength, corrosionresistance, electrical resistivity and temperature stability.

A series of ring electrodes 26 are mounted on the non-conductive cover52 of the generally circular main region 39 of the mapping assembly 17,as shown in FIG. 5. The ring electrodes 26 can be made of any suitablesolid conductive material, such as platinum or gold, preferably acombination of platinum and iridium, and mounted onto the non-conductivecover 52 with glue or the like. Alternatively, the ring electrodes 26can be formed by coating the non-conductive cover 52 with anelectrically conducting material, like platinum, gold and/or iridium.The coating can be applied using sputtering, ion beam deposition or anequivalent technique. A suitable mapping assembly is described in U.S.Pat. No. 7,274,957, the entire disclosure of which is herebyincorporated by reference. If desired, additional electrodes (not shown)could be mounted along the intermediate section 14 and/or the generallystraight proximal section 38.

The contraction puller member 35, for example, a contraction pullerwire, is provided to contract the generally circular main region 39 tothereby change or reduce its diameter, for example, when mapping orablating circular or tubular regions of the heart. The contraction wire35 has a proximal end anchored in the control handle 16, which is usedto manipulate the contraction wire as described further below. Thecontraction wire 35 extends through the central lumen 18 of the catheterbody 12, through the third lumen 32 of the intermediate section 14 andinto the non-conductive cover 52 of the mapping assembly 17. The portionof the contraction wire 35 extending through the non-conductive cover 52is positioned on the side of the generally circular main region 39closer to the center of the generally circular main region, as bestshown in FIG. 6. The center of the generally circular main region refersto the center of the circle formed by the generally circular mainregion. With this arrangement, contraction of the generally circularmain region 39 is dramatically improved over arrangements where theposition of the contraction wire 35 is not so controlled.

As shown in FIGS. 5 and 6, within the mapping assembly 17, thecontraction wire 35 extends through a plastic tube 55. In oneembodiment, the plastic tube 55 comprise three layers, including aninner layer of polyimide over which a braided layer is formed, thebraided layer comprising a braided stainless steel mesh or the like, asis generally known in the art. The braided layer enhances the strengthof the plastic tube 55, reducing the tendency for contraction wire 35 tostraighten the preformed curve of the mapping assembly 17. A thinplastic layer of polytetrafluoroethylene is provided over the braidedlayer to protect the braided layer from getting tangled with the leadwires 40 within the non-conductive cover 52. The plastic tube 55 has aproximal end anchored to the distal end of the intermediate section 14in the third lumen 32 by glue or the like (FIG. 8 a). The support member54 extends through the plastic tube 55 with the contraction wire 35(FIG. 8 a). The distal ends of the support member 54 and the contractionwire 35 are soldered or otherwise attached to a small stainless steeltube 53 (FIG. 7). With this arrangement, the relative positions of thecontraction wire 35 and the support member 54 can be controlled so thatthe contraction wire can be positioned on the side of the generallycircular region 39 closer to the center of the generally circular region39, as described above. The contraction wire 35 on the inside of thecurve pulls the support member 54 to the inside of the curve, enhancingcontraction of the generally circular region 39. Further, when theplastic tube 55 includes a braided layer, it keeps the contraction wire35 from tearing through the non-conductive cover 52.

A third compression coil 46 is situated within the catheter body 12 andintermediate section shaft 14 in surrounding relation to the contractionwire 35 (FIG. 2A). The third compression coil 46 extends from theproximal end of the catheter body 12 and to near the distal end of thethird lumen 32 of the intermediate section 14. The third compressioncoil 46 is made of any suitable metal, such as stainless steel, and istightly wound on itself to provide flexibility, i.e., bending, but toresist compression. The inner diameter of the third compression coil 46is preferably slightly larger than the diameter of the contraction wire35. The outer surface of the compression coil 46 is covered by aflexible, non-conductive sheath 68, e.g., made of polyimide tubing. Thethird compression coil 46 preferably is formed of a wire having a squareor rectangular cross-sectional area, which makes it less compressiblethan a compression coil formed from a wire having a circularcross-sectional area. As a result, the third compression coil 46 keepsthe catheter body 12, and particularly the intermediate section 14, fromdeflecting when the contraction wire 35 is manipulated to contract themapping assembly 17 as it absorbs more of the compression.

The third compression coil 46 is anchored at its proximal end to theouter wall 20 of the catheter body 12 by the proximal glue joint 50 andto the intermediate section 14 by distal glue joint 72.

It is understood that glue joints throughout the catheter 10 maycomprise polyurethane glue or the like. The glue may be applied by meansof a syringe or the like through a hole made in the tubing walls. Such ahole may be formed, for example, by a needle or the like that puncturesthe tubing walls where the needle is heated sufficiently to form apermanent hole. The glue is then introduced through the hole to wickaround the component(s) within the tubing to form a glue joint about theentire circumference of the component(s).

In the depicted embodiment of FIG. 7, the distal end of the mappingassembly 17 is sealed closed with a dome 51 of polyurethane glue or thelike. A short ring 56, made of metal or plastic, and preferablypolyamide, is mounted within the distal end of the non-conductive cover52. The short ring 56 prevents the distal end of the non-conductivecover 52 from collapsing, there by maintaining the diameter of thenon-conductive cover at its distal end.

At the junction of the intermediate section 14 and the mapping assembly17 as shown in FIGS. 8 a and 8 b, the non-conductive cover 52 isattached to the intermediate section 14 by glue or the like. The plastictube 55 has its proximal end inserted and glued in the distal end of theintermediate section 14. The glue (not shown) from the plastic tube 55can further serve to anchor the distal end of the third compression coil46 in place within the third lumen 32. The support member 54 extendsfrom the third lumen 32 into the plastic tube 55 within thenon-conductive cover 52. The proximal end of the support member 54terminates a short distance proximally from the distal end of the thirdlumen 32, approximately about 5 mm, so as not to adversely affect theability of the intermediate section 14 to deflect. However, if desired,the proximal end of the support member 54 can extend proximally furtherinto the intermediate section 14 and/or the catheter body 12.

The lead wires 40 attached to the ring electrodes 26 extend through thefirst lumen 30 of the intermediate section 14 (FIG. 2A), through thecentral lumen 18 of the catheter body 12, through the control handle 16,and terminate at their proximal end in a connector (not shown) which isconnected to an appropriate monitor or other device for receiving anddisplaying the information received from the ring electrodes 26. Theportion of the lead wires 40 extending through the central lumen 18 ofthe catheter body 12, control handle 16 and proximal end of theintermediate section 14 is enclosed within a protective sheath 62, whichcan be made of any suitable material, preferably polyimide. Theprotective sheath 62 is anchored at its distal end to the proximal endof the intermediate section 14 by gluing it in the lead wire lumen 30with polyurethane glue or the like to form glue joint 73.

The lead wires 40 are attached to the ring electrode 26 by anyconventional technique. In one embodiment, each ring electrode 26 ismounted by first forming a hole in the non-conductive cover 52. Anelectrode lead wire 40 is fed through the hole, and the ring electrode26 is welded in place over the lead wire and non-conductive cover 52.

With reference to FIG. 1, the control handle 16 comprises a generallyelongated handle housing, which can be made of any suitable rigidmaterial, such as plastic configured through a suitable molding process.In the illustrated embodiment, the housing includes two opposing halves16 a and 16 b that generally mirror each other and are joined by glue,sonic welding or other suitable means along a longitudinal peripheralseam 28 around the housing. In the illustrated embodiment, the crosssection of the handle 16 formed by the opposing halves changes along thelength of the handle. A more distal portion 112 has a smaller, generallyrectangular cross section. A mid-portion 114 has a larger, generallyrectangular cross section. A more proximal portion 116 has a generallycircular cross section.

In the illustrated embodiment of FIGS. 1 and 9, the control handle 16houses components of a deflection control assembly 74 in the mid-portion114. The deflection control assembly includes a deflection member or arm75 that can be directly manipulated by an operator to control deflectionof the intermediate section 14. The deflection arm 75 is rotatable aboutan axis 76 that is generally transverse or perpendicular to thelongitudinal axis of the control handle. The deflection control assembly74 has a rotatable rocker member 78 that acts on the deflection pullermembers 42 to deflect the intermediate section 14. The rocker member 78has a length L dimension, a width W dimension and a thickness Tdimension (FIGS. 10 and 11).

Along its thickness dimension T, the rocker member 78 is configured withtwo opposing annular formations 140 a and 140 b that define a centralhole or passage 143 that extends through its entire thickness. Thecentral hole 143 is aligned with the rotational axis 76 of thedeflection arm 75. Along its length dimension L, the rocker member 78also has two smaller holes 146 that oppose each other across the centralhole 143. In each hole sits a pulley 147, for example, a snap bearing(FIG. 12), that has a rotational axis parallel to the axis 76. Eachdeflection puller member 42 enters the rocker member through slots 148and a portion is wound around a respective pulley 147.

As understood by one of ordinary skill in the art, the rocker member 78and the pulleys 147 are arranged such that rotation of the rocker memberin one direction about the axis 76 draws back one puller member 42 todeflect the intermediate section 14 in that direction. With reference toFIGS. 13 a-13 c, as the rocker member 78 is rotated by means of thedeflection arm (as represented by line 75), the pulleys 147 aredisplaced from a neutral position (FIG. 13 a) with one pulley 147drawing a puller member 42 on one side of the catheter body 12 againstits anchored proximal end for deflecting the intermediate section 14toward that side (FIGS. 13 b and 13 c).

Each deflection puller member 42 may comprise multiple segments. Asillustrated in FIG. 9, each deflection puller member has a distal pullerwire 42 a and a proximal fiber 42 b that are joined or connected at alocation within the control handle 16 distal the rocker member 78. Thepuller wire 42 a and the tensile fiber 42 b of each deflection pullermember are connected or secured to each other by a connector 154, e.g.,a crimped brass ferrule covered by shrink tubing. Each puller wire 42 aextends through the catheter body 12 and the intermediate section 14.Each tensile fiber 42 b extends inside the control handle 16. In thismanner, it is the more flexible tensile fibers 42 b that interact withthe pulleys 147 and undergo repeated bending and straightening duringdeflection operations, as they are less prone to bending stress andfatigue failure.

Each puller wire 42 a is made of any suitable metal, such as stainlesssteel or Nitinol. Preferably each puller wire has a low frictioncoating, such as a coating of Teflon® or the like. Each puller wire hasa diameter preferably ranging from about 0.006 inch to about 0.012 inch.Preferably both of the puller wires have the same diameter. Flat pullerwires may be used in place of round puller wires. Their cross sectionaldimensions should be such that they provide comparable tensile strengthsas round puller wires.

Each tensile fiber 42 b may be of a high modulus fiber material,preferably having an ultimate tensile strength substantially in therange of 412-463 ksi (2480-3200 Mpa) such as High Molecular DensityPolyethylene (e.g., Spectra™ or Dyneema™), a spun para-aramid fiberpolymer (e.g., Kevlar™) or a melt spun liquid crystal polymer fiber rope(e.g., Vectran™), or a high strength ceramic fiber (e.g., Nextel™). Theterm fiber is used herein interchangeably with the term fibers in thatthe tensile fiber may be of a woven or braided construction. In anycase, these materials tend to be flexible, providing suitable durabilitywhen used in wrapped engagement with the pulleys and the like forgreater throw in deflecting the catheter tip. Further, they aresubstantially non-stretching, which increases the responsiveness to themanipulation of the control handle, and nonmagnetic so that theygenerally appear transparent to an MRI. The low density of the materialcauses it to be generally transparent to an x-ray machine. The materialscan also be nonconductive to avoid shorting. Vectran™, for example, hashigh strength, high abrasion resistance, is an electrical insulator,nonmagnetic, is polymeric, and has low elongation under sustainedloading conditions.

In the illustrated embodiment of FIG. 9, each tensile fiber 42 b extendsproximally from the connector 154 toward the rocker member 78 where eachis wound around a respective pulley 147 and turns about 180 degrees todouble back toward the distal end of the control handle. Each proximalend of the tensile fiber 42 b is anchored by an anchor assembly 90 thatincludes a pair or racks 92, a slug 94 and a stop 96. The proximal endof each tensile fiber 22 b extends between a channel 91 defined by thepair of racks 92, and the proximal end of each tensile fiber is encasedwithin a molded member or slug 94 sized to fit in and translate in thechannel 91. Proximal the slug are the stops 96 that are adjustablypositioned in a selected location along the racks 92, for example, bymeans of interlocking teeth 98 formed in the racks and the stops toreleasably lock in the selected position against movement. The stops 96are formed so that each respective tensile fiber 42 b can slide throughor below them while blocking the slugs 94 from moving proximally pastthem. Accordingly, the stops 96 limit the proximal movement of the slugs94 and anchor the proximal ends of the tensile fibers 42 b to effectuatedeflection when each is drawn proximally by the deflection controlassembly 74. During assembly of the control handle 16, before the twohousing halves 16 a, 16 b are joined, the stops 96 are selectivelypositioned between the racks 92 to achieve a desirable tension in eachtensile member. The interlocking teeth 98 of the racks 92 and stops 96allow for fine adjustments in setting the tension.

The construction and assembly of the deflection control assembly 74including the deflection arm 75 and a tension adjustment member 101 onthe control handle 16 are described as follows. With reference to FIGS.14 and 14 a, the rocker member 78 of the assembly 74 is situated betweenthe two halves 16 a and 16 b of the control handle 16, with each of itsannular formations 140 a and 140 b extending respectively through anopening 120 a, 120 b formed in the distal portion 114 of each housinghalf 16 a and 16 b.

The annular formation 140 a has recesses 160 (FIG. 10) exposed throughthe opening 120 a (FIG. 15) that receive protrusions 152 projecting froma facing surface 154 of the deflection arm 75 (FIG. 16) to rotationallycouple the deflection arm 75 and the rocker member 78. The protrusions152 can snap fit into the recesses 160 and/or be secured by adhesives,glue, sonic welding and the like. A central circular protrusion 156 fromthe deflection arm 75 fits into the hole 143 circumscribed by theannular formation 140 a of the rocker member 78. A suitable deflectionassembly and control handle are described in co-pending U.S. applicationSer. No. 12/346,834, filed Dec. 30, 2008, entitled DEFLECTABLE SHEATHINTRODUCER, the entire disclosure of which is hereby incorporated byreference. Another suitable deflection assembly with deflectionsensitivity is described in co-pending U.S. application Ser. No.12/211,728, filed Sep. 16, 2008, entitled CATHETER WITH ADJUSTABLEDEFLECTION SENSITIVITY, the entire disclosure of which is herebyincorporated by reference. Therein, a cam that is responsive to adeflection sensitivity knob can vary the separation distance between thetwo pulleys 147, thereby changing the deflection sensitivity of thedeflection arm.

Opposing the deflection arm 75 is the deflection tension adjustmentmember or dial 101 (FIGS. 17 and 20) which is coupled to and indirectlyengaged with the rocker member 78 by various mechanisms and parts andallows an operator to adjust the ease with which the deflection arm 75can be rotated. Mounted primarily on the housing half 16 b, theillustrated embodiment of a tension adjustment assembly 100 includes theadjustment dial 101 (FIG. 17), a locking plate 102 (FIG. 18), a tensioncap screw 103, a retaining nut 136 and a washer 119 (see FIGS. 14 and 14a). A user rotates the dial 101 to adjust the tightness or tension ofthe rotational movement of deflection arm 75 by effectively compressingor releasing the rocker member 78 against the washer 119 (e.g., aBelleville type) and the control handle housing half 16 b.

The dial 101 has a generally circular cross section with acircumferential edge 115 having a friction-inducing surface (FIG. 17). Acentral circular protrusion 105 and a plurality of prongs 106 (FIG. 17)situated along a diameter of the dial project from a surface 104 of thedial 101.

The locking plate 102 is sandwiched between the dial 101 and the handlehousing 16 b (FIG. 20). The locking plate 102 (FIG. 18) has a centrallarger hole 107 and two smaller holes 108, all three of which extendthrough the entire thickness of the locking plate. The two prongs 106 ofthe dial 101 are adapted to be inserted through the smaller holes 108 inthe plate 102 (FIG. 21) and received in semi-circular grooves 109 (FIG.19) formed in an outer surface of the housing half 16 b. The grooves 109limit the degree of rotation of the dial 101 in clockwise andcounterclockwise directions. The central hole 107 of the plate 102 (FIG.18) has different cross-sections that include a larger circularcross-section 107 a and a smaller circular cross-section 107 b. Thelarger circular cross-section 107 a receives a head 112 of a cap screw103, and the smaller circular cross-section 107 b receives a threadedbody 115 of the cap screw 103 (FIG. 14 a).

The threaded body 115 of the cap screw 103 extending through the centralhole 107 of the locking plate 102 engages the retaining nut 136 situatedin the opening 143 of the rocker member 78. A head 115 of the nut abutsand is anchored against a neck 132 formed in the inner surface of theopening 143 of the rocker member 78. The opening 120 b in the housinghalf 16 b (FIG. 21) has a larger cross section 122 and a smaller crosssection 124. The smaller cross section 124 has a polygonal shape whichmatches a polygonal (e.g., hexagonal) end 126 of the nut 136 so that thenut 136 is effectively locked against rotation relative to the housinghandle 16 b.

The central protrusion 105 of the dial 101 (FIG. 17) forms a press orinterference fit with the head 112 of the cap screw 103 to createrotational alignment between these two components. The prongs 106 of thedial 101 lock and rotationally couple the dial 101 and the lock plate102, and the cap screw 103 is rotationally coupled to the locking plate102. Coupling of the dial 101 and the locking plate 102 may also beachieved by means of welding the two components together. In that case,the prongs 106 need not protrude from the dial 101 but can insteadextend from the locking plate 102.

Between the polygonal end 126 of the nut 136 and the housing handle 16 bis the washer 119 whose compression against the nut 136 and the housinghandle 16 b is adjustable by the user's rotation of the dial 101 whichtightens or releases the engagement between cap screw 103 and the nut136, thus increasing or decreasing the ease with which the rocker member78 and hence the deflection arm 75 can be rotated.

Components that extend through the control handle, including, forexample, the lead wires 40 and the contraction wire 35 also enter thecontrol handle at the distal end. In the illustrated embodiment of FIG.9, these components extend along the longitudinal axis of the controlhandle. A protective tubing 152 through which the components extend canbe provided, positioned between the two deflection puller members 42 andthrough a channel 150 form through the width dimension W of the rockermember 78 (FIG. 11). Distal and proximal portions of the channel 150have indents, e.g., triangular or wedge-shaped, 151 (FIGS. 9 and 11) toallow the rocker member 78 to rotate freely within a predetermined rangeof angles, e.g., about ±45 degrees of the longitudinal axis of thecontrol handle 16, without interference by the tubing 152 and thecomponents therethrough.

Alternatively, the components extending through the control handle, withthe exception of the contraction wire 35, are routed on an off-axis path153 diverging from the deflection puller members 42 at entry into thedistal end of the control handle 16. The components thus extend alongthe periphery of the housing handle, bypassing the rocker member 78.

It is understood that the distance between the distal end of thecompression coils 44 and the distal anchor sites of each deflectionpuller members 42 in the intermediate section 14 determines thecurvature of the intermediate section 14 in the direction of thedeflection puller members. For example, an arrangement wherein the twodeflection puller members 42 are anchored at different distances fromthe distal ends of the compression coils 44 allows a long reach curve ina first plane and a short reach curve in a plane 90.degree. from thefirst, i.e., a first curve in one plane generally along the axis of theintermediate section 14 before it is deflected and a second curve distalto the first curve in a plane transverse, and preferably normal to thefirst plane. The high torque characteristic of the catheter intermediatesection 14 reduces the tendency for the deflection in one direction todeform the deflection in the other direction. Suitable deflectioncontrol handles and parts thereof for use with such a catheter aredescribed in U.S. patent application Ser. No. 08/924,611, filed Sep. 5,1997, entitled “Omni-Directional Steerable Catheter”, Ser. No.09/130,359, filed Aug. 7, 1998, entitled “Bi-Directional Control Handlefor Steerable Catheter”, and Ser. No. 09/143,426, filed Aug. 28, 1998,entitled “Bidirectional Steerable Catheter with Bidirectional ControlHandle”, the entire disclosures of which are hereby incorporated byreference.

For adjusting the mapping assembly 17 by means of a third puller member,e.g., the contraction wire 35, a distal end of the contraction wireextending between the two deflection puller members 42 within thecontrol handle 16 is anchored in the control handle for actuation bymeans of a linear control assembly 300 housed in the proximal portion116 of the control handle. In the illustrated embodiment of FIG. 23, thelinear control assembly 300 includes a linear control member 302, afixed cam 306 whose body 307 supports a rotational member 304, thecombination of which effectuates longitudinal movement of thecontraction wire 35 relative to the catheter body 12, for example, tocontract and expand the mapping assembly 17. In the disclosedembodiment, the linear control assembly 300 is positioned proximal thedeflection control assembly 74, although it is understood that it can bepositioned distal the deflection control assembly 74.

With reference to FIGS. 23-27, the proximal portion 116 of the controlhandle 16 in which the linear control assembly is housed has a generallycircular cross section of an inner diameter D1 and an outer diameter D2.The cam 306 has a collar 309 and a barrel body 307. The collar is sizedso that it can be received in an inner circumferential groove 260 (FIG.15) formed in the control handle housing halves 16 a and 16 b. Thecollar is affixed therein by glue or the like so the cam is fixedrelative to the control handle 16. The rotational member 304 is mountedon the body 307 of the cam 36 so that it can rotate on the cam inresponse to linear movement of the control member 302 along alongitudinal axis 310 of the control handle.

To convert linear movement of the linear control member 302 intorotational movement of the rotational member 304, the member 304 has ahelical track 305 formed in its outer surface that extends between adistal end and a proximal end of the member 304. The linear controlmember 302 has an outer portion 311, a thinner portion 312, a widerportion 314, and a projection 303 (FIG. 24). To couple the controlmember and the inner rotational member, the projection 303 is receivedin the track 305 through an opening formed by a recess opening 350 (FIG.15) formed in each control handle housing halves 16 a, 16 b for thethinner portion 312. The wider portion 314 has a width dimension (betterseen in FIGS. 26 and 27) that conforms to a cutout formation 307 (FIG.15) below the recess opening 350 in the housing halves 16 a, 16 b sothat the linear control member 302 does not detach from the controlhandle 16. The longitudinal dimensions of the recess 350 and 307 whichare both greater than the length of the linear control member 302 allowthe control member and the control handle to slidably engage each otherthus allowing distal and proximal linear movement of the control memberalong the longitudinal axis, as actuated by user to advance or retractthe third puller member.

The body 307 of the cam 306 on which the rotational member 304 issupported also has a helical track 332 formed in an outer surface of thebody 307. The track 332 extends between the collar 309 and a proximalend of the body. Riding in the track 332 is a finger 341 of a follower340 generally situated between the cam 306 and the inner rotationalmember 304, whose movement is guided by an axial slot 342 formed in therotational member 304 as the rotational member is rotated by the linearcontrol member 302 by means of the projection 303 received in thehelical track 305. A distal end of the contraction wire 35 is anchoredto the finger 341 so that the follower 340 can move the contraction wire35 longitudinally relative to the catheter body 12.

As a user moves the control member 302 linearly along the longitudinalaxis 310, the projection 303 rotates the rotational member 304 by meansof the track 305 thereon. As the rotational member 304 and its axialslot 342 rotate, so does the follower 340 within the slot 342, with allthree orbiting the longitudinal axis of the cam and the control handle16. As the follower 340 orbits, it finger 341 slides in the helicaltrack 332 to move distally or proximally relative to the control handle16. As the follower 340 slides distally, the contraction wire 35 ispushed distally to expand the mapping assembly 17. As the follower 340slides proximally, the contraction wire is drawn proximally to contractthe mapping assembly 17. Such is a means by which linear movement of thecontrol member 302 is converted to a rotational movement by which thecontraction puller member 35 is advanced or retracted within the controlhandle. Advantageously, the distance the follower 340 can travel alongthe helical track 332 is not limited to and in fact can be much greaterthan the length of the cylindrical body 307, for greater range or degreeof motion in the catheter component controlled by the contraction wire35. Indeed, the distance the follower 340 can travel (and hence amountby which the contraction wire 35 can be moved) along the cylindricalbody 307 depends on the pitch of the helical track 332 (e.g., width ofone complete helix turn) and the diameter of the cylindrical body 207.

The collar 309 of the cam 306 has a radial notch 344 through which thecontraction wire 35 passes to reach the body 307. A lip 349 is formed atthe proximal end of the body 307 of the cam 306 as a snap-fit feature toretain the rotational member 304 on the body 307. Axial notches 346allow deformation or deflection of the proximal end of the cam 307 tofacilitate the snap-fit feature. Lead wires and other components (e.g.,thermocouple wires, cables, irrigation tubing) extending through theprotective tubing 152 can pass through passage 348 of the cam.

In an alternate embodiment, the linear control assembly includes asecond linear control member 302 b that diametrically opposes a firstlinear control member 302 a on the control handle 16, as illustrated inFIGS. 28-31. Each linear control member has a projection 303 a, 303 bthat engages a respective one of double helical tracks 305 a and 305 bprovided on the inner rotational member 304. As illustrated in FIG. 32,the linear control members 302 a, 302 b slidably engage the controlhandle housing halves by means of opposing cutout formations 307 a, 307b, respectively, and the projections 303 a, 303 b reaches the innerrotational member 304 through recess openings 350 a, 350 b,respectively. Thus, the user can use either linear control member toexpand or contract the mapping assembly, where both linear controlmembers move similarly and contemporaneously in response to actuation ofeither linear control member by the user.

In either of the foregoing embodiments, as a user pushes or pulls on alinear control member, the projection on the linear control member movesdistally or proximally in a linear fashion which slides in a helicaltrack on the rotational member to rotate the rotational member. As therotational member rotates about the cam, its axial slot guides thefollower to orbit about the cam. The follower slides in the cam trackmoving distally or proximally relative to the control handle. As thefollower slides distally, the contraction wire is pushed distally, forexample, to expand the mapping assembly. As the follower slidesproximally, the contraction wire is drawn proximally, for example, tocontract the mapping assembly.

It is understood that relative sizing of the components of the controlassembly is not limited to the illustrated embodiments. Advantageously,the control assembly utilizes minimal space in the control handle formaximizing contraction and expansion of the mapping assembly byconverting linear motion of the control member into rotational motion ofthe inner member which retracts and advances (or releases) thecontraction wire in a linear fashion. For either embodiment, a suitablelength L of the cam track about the cam can be L=Pi*(D_(E)−D_(C)) whereD_(E) is the expanded diameter of the generally circular main portion 39of the mapping assembly 17 and D_(C) is the contracted diameter of thegenerally circular main portion 39.

In use, a suitable guiding sheath is inserted into the patient with itsdistal end positioned at a desired mapping location. An example of asuitable guiding sheath for use in connection with the present inventionis the Preface™. Braiding Guiding Sheath, commercially available fromBiosense Webster, Inc. (Diamond Bar, Calif.). The distal end of thesheath is guided into one of the chamber, for example, the atria. Acatheter in accordance with the present invention is fed through theguiding sheath until its distal end extends out of the distal end of theguiding sheath. As the catheter is fed through the guiding sheath, themapping assembly 17 is straightened to fit through the sheath. Once thedistal end of the catheter is positioned at the desired mappinglocation, the guiding sheath is pulled proximally, allowing thedeflectable intermediate section 14 and mapping assembly 17 to extendoutside the sheath, and the mapping assembly 17 returns to its originalshape due to the shape-memory of the support member 54.

By manipulating and rotating the deflection arm 75 of the deflectioncontrol assembly 74 to deflect the intermediate section 14, the mappingassembly 17 is then inserted into a pulmonary vein or other tubularregion (such as the superior vena cava, or inferior vena cava) so thatthe outer circumference of the generally circular main region 39 of theassembly 17 is in contact with a circumference inside the tubularregion. Turning the deflection arm 75 in one direction deflects theintermediate section 14 to that direction. Turning the deflection 75 inthe opposite direction deflects the intermediate section 14 to thatopposite direction. Tension of the deflection 75 is adjusted bymanipulating and rotating the dial 101. Turning the dial 101 in onedirection increases the tension. Turning the dial 101 in the oppositiondirection decreases the tension. Preferably at least about 50%, morepreferably at least about 70%, and still more preferably at least about80% of the circumference of the generally circular main region is incontact with a circumference inside the tubular region.

The circular arrangement of the electrodes 26 permits measurement of theelectrical activity at that circumference of the tubular structure sothat ectopic beats between the electrodes can be identified. The size ofthe generally circular main region 39 permits measurement of electricalactivity along a diameter of a pulmonary vein or other tubular structureof or near the heart because the circular main region has a diametergenerally corresponding to that of a pulmonary vein or other tubularstructure. By manipulating the linear control member of the controlassembly, the assembly 17, in particular, the generally circular mainregion 39, is adjusted to fit the pulmonary vein or other tubularstructure. By pulling back on a linear control member, the contractionwire is drawn proximally to tighten and decrease the diameter of thegenerally circular region 39. By pushing forward on a linear controlmember, the contraction wire is pushed distally to release the generallycircular region 39 and expands its diameter.

The preceding description has been presented with reference to presentlypreferred embodiments of the invention. Workers skilled in the art andtechnology to which this invention pertains will appreciate thatalterations and changes in the described structure may be practicedwithout meaningfully departing from the principal, spirit and scope ofthis invention. For example, the catheter can be adapted such that thethird puller member advances and retracts another component such as aguide wire or a needle. As understood by one of ordinary skill in theart, the drawings are not necessarily to scale. Accordingly, theforegoing description should not be read as pertaining only to theprecise structures described and illustrated in the accompanyingdrawings, but rather should be read consistent with and as support tothe following claims which are to have their fullest and fair scope.

What is claimed is:
 1. A catheter comprising: a catheter body; adeflectable intermediate section distal the catheter body; a mappingassembly distal the intermediate section, the mapping assembly having agenerally circular portion; a control handle proximal the catheter body,the control handle having a longitudinal axis and comprising: adeflection control assembly; and a linear control assembly having acontrol member, an inner rotational member, and a cam fixed againsttranslational and rotational movement relative to the control handle,the control member adapted for linear movement along the longitudinalaxis of the control handle; first and second puller members responsiveto the deflection control assembly adapted to deflect the intermediatesection; and a third puller member responsive to the linear controlassembly adapted to contract the generally circular portion of themapping assembly.
 2. A catheter of claim 1, wherein a proximal end ofthe third puller member is anchored in the linear control assembly, suchthat linear movement of the control member along the longitudinal axisof the control handle by a user moves the third puller memberlongitudinally relative to the catheter body.
 3. A catheter of claim 1,wherein the inner rotational member is rotatably mounted on the cam andthe control member has a projection adapted to rotate the innerrotational member and, wherein the linear control assembly furtherincludes a follower to which the proximal end of the third puller memberis anchored, the follower being adapted to follow movement of the innerrotational member by sliding in a cam track on the cam.
 4. A catheter ofclaim 3, wherein the cam track is helical about a body of the cam.
 5. Acatheter of claim 3, wherein the projection is received in a track onthe inner rotational member and is adapted to rotate the innerrotational member as the control member moves relative to the controlhandle along the longitudinal axis of the control handle.
 6. A catheterof claim 5, wherein the projection extends through a recess opening inthe control handle to reach the track on the inner rotational member. 7.A catheter of claim 5, wherein the projection has a wide portion thatslidably engages a housing of the control handle.
 8. A catheter of claim1, wherein the cam and the inner rotational member have a commonrotational axis.
 9. A catheter of claim 5, wherein the track on theinner rotational member is helical.
 10. A catheter of claim 1, whereinthe linear control assembly is proximal of the deflection controlassembly.
 11. A catheter of claim 1, further comprising a tensioncontrol assembly adapted to adjust tension of the deflection controlassembly.
 12. A multifunctional catheter control handle, comprising: ahousing; a deflection control assembly having a deflection arm and arocker member; a linear control assembly having a linear control member,an inner rotational member and a cam fixed against translational androtational movement relative to the control handle, the inner rotationalmember being rotatably mounted on the cam; at least one deflectionpuller member with a proximal end anchored to the deflection controlassembly; and a contraction puller member with a proximal end anchoredto the linear control assembly.
 13. A control handle of claim 12,wherein the linear control member is mounted on the housing, the linearcontrol member having: a portion that slidably engages the housing, anda projection that engages the inner rotational member through an openingin the housing.
 14. A control handle of claim 13, wherein the projectionis received in a track on the inner rotational member so that linearmovement of the linear control member rotates the inner rotationalmember.
 15. A control handle of claim 14, wherein the linear controlassembly includes a follower to which the proximal end of thecontraction puller member is anchored, the follower being responsive torotational movement of the inner rotational member by sliding in a camtrack on the cam to thereby move the contraction puller member relativeto the catheter body to expand or contract the mapping assembly.
 16. Acontrol handle of claim 15, wherein the follower is situated in a slotin the inner rotational member, the slot adapted to guide movement ofthe follower to advance or retract the contraction puller member.
 17. Acontrol handle of claim 14, wherein the track on the inner rotationalmember is helical.
 18. A control handle of claim 15, wherein the camtrack is helical.
 19. A control handle of claim 12, wherein the innerrotational member and the cam have a common longitudinal axis that iscoaxial with a longitudinal axis of the control handle.
 20. A controlhandle of claim 12, further comprising a tension control assembly.